1. Field of the Invention
The present invention relates to a component mounting method and a component mounting device for executing a component mounting process on a substrate by repeating a mounting turn by a mounting head on each of substrates which are positioned by two substrate carrying lines.
2. Description of Related Art including information disclosed under 37 C.F.R. 1.97 and 1.98
<Background Art>
A printed circuit board fabrication line includes a solder printer for printing solder on a substrate, a component mounting device for mounting components (electronic components) on the substrate on which the solder has been printed by the solder printer and a reflow oven where reflow soldering is executed on the substrate on which the components are packaged by the component mounting device, which are arranged consecutively along the carrying direction of substrates. In these constituent units, the component mounting device includes substrate carrying lines where substrates are carried and positioned, a component feeding unit for feeding components, and a mounting head for executing a component mounting process on a substrate by repeating a mounting turn including a series of operations ranging from picking up components fed in by the component feeding unit to mounting the components so picked up on to the substrate.
Among component mounting devices of this type, there is known a component mounting device in which two substrate carrying lines are arranged side by side in a front-to-rear direction of a base table and the component mounting process is executed on each of substrates which are carried in and positioned by the two substrate carrying lines by two mounting heads provided and arranged in the front-to-rear direction of the base table. In the component mounting device described, components can be mounted on substrates by selecting either of an alternating mounting mode in which the component mounting process is executed by the two mounting heads on substrates which are positioned alternately by the two substrate carrying lines and an independent mounting mode in which the component mounting process is executed independently by the two mounting heads on substrates which are positioned by the substrate carrying lines lying closer to the mounting heads (for example, Patent Document 1).
When the component mounting device executes the component mounting process on substrates in the alternating mounting mode, components to be mounted on substrates only have to be distributed to either of the components feeders which are arranged in the front-to-rear direction of the base table, and therefore, the number of parts feeders installed in the base table can be reduced. This enables the use of a component mounting device having a narrow base table, providing an advantage that an increase in length of the printed circuit board fabrication line can be suppressed. On the other hand, when the component mounting device executes the component mounting process on substrates in the independent mounting mode, even in the event that the component mounting process cannot be performed on a substrate positioned by one of the substrate carrying lines (for example, due to the running out of components), the component mounting process may be executed continuously on a substrate positioned by the other substrate carrying line, providing an advantage that there is caused no such situation that the printed circuit board fabrication operations of the printed circuit board fabrication line are not totally stopped.